New member, new to baking /cooking

i was asked to bake for easter for my families restaurant. I started baking last year and I am a little nervous but I love doing it and I get paid for it ... I want to make carrot cake but in a sheet pan. I have no idea how to know how much to make. Should I just make 3 or four batches for a sheet pan size or just double or triple the recipe? If anyone can help that would be great. If I enjoy it this year I am think of taking classes. I'm only a home cook so I've only ever baked for 12-24 portions but for easter I have to make enough for 500 people. If anyone can give me insight I will message you what I need and will make and maybe you could help me. Thank you

I believe there was just the other day a thread on baking carrot cake in a large restaurant sized sheet pan. Don't use the search function, try looking through the last week's threads in baking and in cooking and in recipes.